Hazard Notification System (HANS) for Volcanoes

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HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Monday, August 29, 2022, 5:13 PM HST (Tuesday, August 30, 2022, 03:13 UTC)


TA'U ISLAND VOLCANO (VNUM #244001)
14°13'48" S 169°27'14" W, Summit Elevation 3054 ft (931 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW

The earthquake swarm related to Taʻū Island continues. Activity has not changed significantly since yesterday’s daily update. Data from the new seismometers confirms that the source location of earthquakes has not moved for many days. This tells us that the cause of the earthquakes has not shifted within the earth. 

The American Samoa Emergency Operations Center did not receive any felt reports for the past 24 hours. However, the USGS seismic network detected at least 30 earthquakes that were large enough to be felt by people on the Manuʻa Islands. The largest event occurred at 12:56 AM SST today. There are many more small earthquakes that are undetectable by humans. 

In the coming weeks, USGS staff will install Global Positioning System (GPS) receivers to improve the Manuʻa Islands’ monitoring network. The GPS equipment will detect very slight movements of the ground. As a result, GPS data will help us better understand what is happening beneath the ground and provide more accurate hazard assessments. 

On Sunday, USGS and NOAA National Weather Service staff met with the Department of the Interior Assistant Secretary for the Office of Insular and International Affairs. Discussion included the ongoing earthquakes at Taʻū Island, natural hazard monitoring in the Pacific Islands, and ways to encourage local youth to become interested in becoming scientists. 

Samoan and English language alert level and color code definitions: (PDF download, 57.68 kb) https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/media/files/VOLCANO%20AVIATION%20CODES%20AND%20ALERT%20LEVELS.pdf 

 



Possible Hazards

It is unclear if this earthquake unrest will escalate to a volcanic eruption and exactly where an eruption might occur. An eruption could pose significant hazards to residents of American Samoa; these hazards include volcanic gases, volcanic ash, low-level localized explosions of lava, lava flows, earthquake shaking, and tsunami. Information about these hazards, which are like those in Hawaii, can be found at this HVO website: https://www.usgs.gov/observatories/hvo/hazards. 

The primary hazard of concern at this time is earthquake shaking, although no physically damaging earthquakes have occurred as part of this swarm. For information on how to prepare for an earthquake, see: https://www.usgs.gov/faqs/what-can-i-do-be-prepared-earthquake

If you feel shaking and are not near the coast, immediately drop, cover, and hold on until the shaking stops. If you are at the coast, heed the natural tsunami warning signs. If you feel a strong or long-duration earthquake, see a sudden rise or fall of the ocean, hear a loud roar from the ocean, or see a large aerial plume from an eruption, a tsunami may follow, and you should immediately move to higher ground.  Pacific Tsunami Warning Center: https://tsunami.gov/

Volcano Monitoring

Volcanoes in the Manuʻa Islands are monitored with a limited real-time seismic network consisting of three sophisticated seismometers —two on Taʻū Island and one on Ofu Island—and six microseismometers on Tutuila, Taʻū, and Ofu-Olosega Islands. Satellite remote sensing is another tool being used, which may detect heat, volcanic gas, and volcanic ash associated with early phases of volcanic activity.

Report what you feel and see.

Residents can assist these monitoring efforts by noting and reporting accurate times that they feel earthquake shaking or notice other changes that might be related to volcanic activity to either the Pago Pago National Weather Service Office (https://www.weather.gov/ppg/wsopagooffice) or the American Samoa EOC in Pago Pago (684-699-3800).  

American Samoa Volcanoes

Volcanoes in the U.S. Territory of American Samoa are within the area of responsibility of the U.S. Geological Survey’s Hawaiian Volcano Observatory, based in Hilo on the Island of Hawai‘i.

NOAA Weather and Tsunami resources



The Hawaiian Volcano Observatory is one of five volcano observatories within the U.S. Geological Survey and is responsible for monitoring volcanoes and earthquakes in Hawaiʻi and American Samoa.



CONTACT INFORMATION:

HVO, askHVO@usgs.gov—best contact for regular reporting and questions. 
Ken Hon, HVO Scientist in Charge, USGS khon@usgs.gov
Natalia Deligne, American Samoa Lead Responding Scientist, USGS ndeligne@usgs.gov 



Subscribe to these messages: https://volcanoes.usgs.gov/vns2/
Summary of volcanic hazards from eruptions: https://www.usgs.gov/observatories/hvo/hazards
Recent earthquakes in Hawaiʻi (map and list): https://www.usgs.gov/observatories/hvo
Volcanoes of American Samoa: https://www.usgs.gov/observatories/hvo/volcanoes-american-samoa
Explanation of Volcano Alert Levels and Aviation Color Codes: https://www.usgs.gov/programs/VHP/volcanic-alert-levels-characterize-conditions-us-volcanoes